A meta-analysis of 17 studies finds that smokers 60 or older who give up cigarettes later in life can still see health benefits. Researchers from the German Cancer Research Center in Heidelberg, Germany, led by Hermann Brenner, MD, looked at the risk of all-cause mortality in smokers 60 or older and found that regardless of age, the risk of dying in a given time frame from any cause is sharply increased in smokers compared with people who have never smoked. However, increased risk decreases in people who quit, and that benefit is still present even after age 80, the researchers found.

Their findings appear in the journal Archives of Internal Medicine.

The researchers examined 17 cohort studies that included men and women 60 and older. They found that point estimates of relative mortality for smokers compared with never smokers ranged from 1.3 to 3.4 for men and 1.2 to 2.5 for women. A meta-analysis of the studies found the relative mortality compared with never smokers was 1.83 (95% CI from 1.65 to 2.03) over all ages and both sexes. The relative mortality fell slightly with age but remained high—1.94 for ages 60 through 69, 1.86 for ages 70 through 79, and 1.66 for 80 and older.

The researchers point out that the decline with age in relative mortality that was observed is likely due to a “depletion of susceptibilities” effect, in which smokers most likely to die of the habit have already done so.

A similar pattern was observed in former smokers. The relative mortality compared with never smokers was 1.34, but it was 1.54 among people ages 60 through 69, 1.36 among those ages 70 through 79, and 1.27 in those 80 and older. This difference in relative mortality rates for former and current smokers amounted to a risk reduction of 28% for those who quit.

In addition, a similar calculation for the different age groups suggested that even at 80 or older, those who quit have a 24% reduction in the risk of death compared with current smokers of that age.

The researchers report some limitations with the analysis, including the fact that the involved studies had varying follow-up periods and age ranges. Also, the age ranges did not always match the age ranges chosen for the age-specific meta-analysis. Still, the findings emphasize the need for effective public health messages, as many older smokers mistakenly believe that they are too old to quit and to see any benefit from doing so, commented Tai Hing Lam, MD, from the University of Hong Kong in Pokfulam.

Source: Archives of Internal Medicine